JasperReports: How to add a WHERE statement in SQL query depending on a Boolean parameter?

Question

How can I add a sub where statement in SQL if my Boolean parameter is true in JasperReports?
For example, I have my SQL as below:

SELECT * FROM shop         


        

Answer 1

You can do that direct in SQL

SELECT * FROM shops WHERE region = "Canada"
AND (@param <> `True` OR isActive = 'Y')
-----^^^^^^^^^^^^^^^^--<< Condition: Your param is not true------
ORDER BY name